<template>
  <div id="map">
    <div id="mouse-position" ref="mouse"></div>
  </div>
</template>

<script lang="ts" setup>
import { onMounted, ref, onBeforeUnmount, Ref } from 'vue'
import { Map, View } from 'ol'
import { MousePosition, defaults } from 'ol/control'
import { createStringXY } from 'ol/coordinate'
import { Tile as TileLayer } from 'ol/layer'
import { XYZ } from 'ol/source'
import { MAPURL, ATTRIBUTIONS } from '../../constants'

const raster = new TileLayer({
  source: new XYZ({
    attributions: ATTRIBUTIONS,
    url: MAPURL,
    maxZoom: 20
  })
})
const mouse: Ref<HTMLElement | null> = ref(null)

let map: Map | null = null
//实例化鼠标位置控件（MousePosition）
const mousePositionControl = (target: HTMLElement) =>
  new MousePosition({
    //坐标格式
    coordinateFormat: createStringXY(4),
    //地图投影坐标系（若未设置则输出为默认投影坐标系下的坐标）
    projection: 'EPSG:4326',
    //坐标信息显示样式类名，默认是'ol-mouse-position'
    className: 'custom-mouse-position',
    //显示鼠标位置信息的目标容器
    target,
    //未定义坐标的标记
    undefinedHTML: '&nbsp;'
  })
const initMap = (mousePositionControl) => {
  map = new Map({
    //初始化map
    target: 'map',
    //地图容器中加载的图层
    layers: [
      //加载瓦片图层数据
      raster
    ],
    view: new View({
      projection: 'EPSG:4326', // 坐标系，有EPSG:4326和EPSG:3 857
      center: [0, 0],
      //地图初始显示级别
      zoom: 5
    }),
    //加载控件到地图容器中
    controls: defaults({
      //地图中默认控件
      attributionOptions: {
        //地图数据源信息控件是否可收缩,默认为true
        collapsible: true
      }
    }).extend([mousePositionControl]) //加载鼠标位置控件
  })
}
onMounted(() => {
  if (mouse.value === null) return
  initMap(mousePositionControl(mouse.value))
})

onBeforeUnmount(() => {
  if (map) {
    map.dispose()
    map = null
  }
})
</script>

<!-- Add "scoped" attribute to limit CSS to this component only -->
<style scoped>
#map {
  position: relative;
  width: 100%;
  height: calc(100% - 50px);
}

#mouse-position {
  position: absolute;
  left: 50%;
  top: 20px;
  transform: translateX(-50%);
  color: red;
  font-weight: bold;
  z-index: 1;
}
</style>